On 12/13/07, Stephen Neuendorffer <[EMAIL PROTECTED]> wrote:
> This now better describes what the UBoot device tree generator actually does.
> In particular:
>
> 1) Nodes have a label derived from the device name, and a node name
> derived from the device type.
> 2) Usage of compound nodes (representing more than one device in the same IP)
> which actually works. This requires having a valid compatible node, and all
> the other things that a bus normally has. I've chosen 'xlnx,compound' as the
> bus name to describe these compound nodes.
> 3) Uartlite requires a port-number property for the console to work.
>
> In addition, I've clarified some of the language relating to how mhs
> nodes should be represent in the device tree.
Thanks for the updates. Comments below.
> ---
> Documentation/powerpc/booting-without-of.txt | 61
> +++++++++++++++-----------
> 1 files changed, 36 insertions(+), 25 deletions(-)
>
> diff --git a/Documentation/powerpc/booting-without-of.txt
> b/Documentation/powerpc/booting-without-of.txt
> index e9a3cb1..5e2b85a 100644
> --- a/Documentation/powerpc/booting-without-of.txt
> +++ b/Documentation/powerpc/booting-without-of.txt
> @@ -2276,7 +2276,7 @@ platforms are moved over to use the
> flattened-device-tree model.
> properties of the device node. In general, device nodes for IP-cores
> will take the following form:
>
> - (name)@(base-address) {
> + (name): (ip-core-name)@(base-address) {
(name): (generic-name)@(base-address) {
> compatible = "xlnx,(ip-core-name)-(HW_VER)"
> [, (list of compatible devices), ...];
> reg = <(baseaddr) (size)>;
> @@ -2294,9 +2294,9 @@ platforms are moved over to use the
> flattened-device-tree model.
> dropped from the parameter name, the name is converted
> to lowercase and all underscore '_' characters are
> converted to dashes '-'.
> - (baseaddr): the C_BASEADDR parameter.
> + (baseaddr): the baseaddr parameter value (often named C_BASEADDR).
> (HW_VER): from the HW_VER parameter.
> - (size): equals C_HIGHADDR - C_BASEADDR + 1
> + (size): the address range size (often C_HIGHADDR - C_BASEADDR
> + 1).
Ah, yes. Good clarification.
>
> Typically, the compatible list will include the exact IP core version
> followed by an older IP core version which implements the same
> @@ -2326,12 +2326,13 @@ platforms are moved over to use the
> flattened-device-tree model.
>
> becomes the following device tree node:
>
> - [EMAIL PROTECTED] {
> + opb_uartlite_0: [EMAIL PROTECTED] {
> device_type = "serial";
> compatible = "xlnx,opb-uartlite-1.00.b";
> reg = <ec100000 10000>;
> - interrupt-parent = <&opb-intc>;
> + interrupt-parent = <&opb_intc_0>;
> interrupts = <1 0>; // got this from the opb_intc parameters
> + port-number = <0>;
> current-speed = <d#115200>; // standard serial device prop
> clock-frequency = <d#50000000>; // standard serial device prop
> xlnx,data-bits = <8>;
> @@ -2339,16 +2340,19 @@ platforms are moved over to use the
> flattened-device-tree model.
> xlnx,use-parity = <0>;
> };
>
> - Some IP cores actually implement 2 or more logical devices. In this case,
> - the device should still describe the whole IP core with a single node
> - and add a child node for each logical device. The ranges property can
> - be used to translate from parent IP-core to the registers of each device.
> - (Note: this makes the assumption that both logical devices have the same
> - bus binding. If this is not true, then separate nodes should be used for
> - each logical device). The 'cell-index' property can be used to enumerate
> - logical devices within an IP core. For example, the following is the
> - system.mhs entry for the dual ps2 controller found on the ml403 reference
> - design.
> + Some IP cores actually implement 2 or more logical devices. In
> + this case, the device should still describe the whole IP core with
> + a single node and add a child node for each logical device. The
> + ranges property can be used to translate from parent IP-core to the
> + registers of each device. In addition, the parent node should be
> + compatible with the bus type 'xlnx,compound', and should contain
> + #address-cells and #size-cells, as with any other bus. (Note: this
> + makes the assumption that both logical devices have the same bus
> + binding. If this is not true, then separate nodes should be used
> + for each logical device). The 'cell-index' property can be used to
> + enumerate logical devices within an IP core. For example, the
> + following is the system.mhs entry for the dual ps2 controller found
> + on the ml403 reference design.
>
> BEGIN opb_ps2_dual_ref
> PARAMETER INSTANCE = opb_ps2_dual_ref_0
> @@ -2370,21 +2374,24 @@ platforms are moved over to use the
> flattened-device-tree model.
>
> It would result in the following device tree nodes:
>
> - [EMAIL PROTECTED] {
> + opb_ps2_dual_ref_0: [EMAIL PROTECTED] {
> + #address-cells = <1>;
> + #size-cells = <1>;
> + compatible = "xlnx,compound";
> ranges = <0 a9000000 2000>;
> // If this device had extra parameters, then they would
> // go here.
> - [EMAIL PROTECTED] {
> + [EMAIL PROTECTED] {
According to the generic names recommendation, this should be either
"[EMAIL PROTECTED]" or "[EMAIL PROTECTED]", but of course the two interfaces are
identical and EDK doesn't have any information about how they are
used. Perhaps the node name should be: "[EMAIL PROTECTED]". David, thoughts?
> compatible = "xlnx,opb-ps2-dual-ref-1.00.a";
> reg = <0 40>;
> - interrupt-parent = <&opb-intc>;
> + interrupt-parent = <&opb_intc_0>;
> interrupts = <3 0>;
> cell-index = <0>;
> };
> - [EMAIL PROTECTED] {
> + [EMAIL PROTECTED] {
> compatible = "xlnx,opb-ps2-dual-ref-1.00.a";
> reg = <1000 40>;
> - interrupt-parent = <&opb-intc>;
> + interrupt-parent = <&opb_intc_0>;
> interrupts = <3 0>;
> cell-index = <0>;
> };
> @@ -2447,17 +2454,18 @@ platforms are moved over to use the
> flattened-device-tree model.
>
> Gives this device tree (some properties removed for clarity):
>
> - plb-v34-0 {
> + plb_v34 {
Steve, when I wrote this I was lazy and I didn't add the bus address.
However, if we don't have the base address I think we'll end up with
name collisions (especially in the MPMC case). So, based on generic
names convention, this should probably simply be "plb@<baseaddr>".
> #address-cells = <1>;
> #size-cells = <1>;
> + compatible = "xlnx,plb-v34-1.02.a";
> device_type = "ibm,plb";
> ranges; // 1:1 translation
>
> - [EMAIL PROTECTED] {
> + plb_bram_if_cntrl_0: [EMAIL PROTECTED] {
Node name should probably just be "[EMAIL PROTECTED]" here.
> reg = <ffff0000 10000>;
> }
>
> - opb-v20-0 {
> + opb_v20 {
opb@<baseaddr>
> #address-cells = <1>;
> #size-cells = <1>;
> ranges = <20000000 20000000 20000000
> @@ -2465,11 +2473,11 @@ platforms are moved over to use the
> flattened-device-tree model.
> 80000000 80000000 40000000
> c0000000 c0000000 20000000>;
>
> - [EMAIL PROTECTED] {
> + opb_uart16550_0: [EMAIL PROTECTED] {
[EMAIL PROTECTED]
> reg = <a00000000 2000>;
> };
>
> - [EMAIL PROTECTED] {
> + opb_intc_0: [EMAIL PROTECTED] {
[EMAIL PROTECTED]
> reg = <d1000fc0 20>;
> };
> };
> @@ -2513,6 +2521,9 @@ platforms are moved over to use the
> flattened-device-tree model.
>
> Requred properties:
> - current-speed : Baud rate of uartlite
> + Optional properties:
> + - port-number : unique ordinal index of the device. This
> + property is required for a console on uartlite.
And has already been discussed, drop the port-number property. I'll
rework the uartlite driver to use aliases instead.
Cheers,
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
[EMAIL PROTECTED]
(403) 399-0195
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